


Walk with the Devil

by idontevenknow (idontevenknowugh)



Series: Walk with the Devil [1]
Category: Undertale (Video Game)
Genre: Captivity, Drabbles, Experimentation, Gen, Horror, Injury, Restraints
Language: English
Status: Completed
Published: 2018-06-02
Updated: 2018-06-05
Packaged: 2019-05-17 07:29:16
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 5
Words: 2,623
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14828030
Author URL: https://archiveofourown.org/users/idontevenknowugh/pseuds/idontevenknow
Summary: Sans has been warned.





	1. He ain't what he seems

It lays there, limbs splayed around like it fell to its current resting spot. Water pools around it, coming up just enough to cover its spine. More trickles down, striking its left foot, directly above its right socket, and one rib right before it curves down towards the rest of the water. It’s the only movement in the small chamber.  
  
Sans is still outside of the room, the toes of his shoes just coming up to the line he’s not supposed to cross. He won’t cross it! … but he can’t help looking.  
  
It kind of reminds him of his dad, slender and tall. He thinks it would be graceful, if it moved. He had worked beside his father for the past 5 years and never seen it so much at twitch. The warmth of magic didn’t touch it’s joints. It hadn’t ever spoken or looked at him.  
  
His dad told him that it was restrained, though nothing physical bound it. Sans can see the machinery embedded in the rock walls that make up its cage. He’d never been told how they worked, but he knew enough to guess.  
  
Whatever dampening power they have must be immense, to break down its joints. Yet, somehow, it maintains its physical form. He wonders what its soul looks like.  
  
It isn’t a monster, he could hear his dad reminding him, exasperated. He frowns at the still form. In every way, it looks just like Sans himself. Well, maybe not just like. When Sans imagines it standing, it towers over him. Even for a real skeleton, Sans is very short.  
  
He sighs, wondering if he hopes it will do something some day. He knows that his urge to check on it is just a natural reaction to the forbidden. Sans wants to do what he’s been told not to do out of sheer curiosity. It could no more move than the rocks it lays on. Not while his dad’s machines operate.  
  
Sans could easily mistake it for dead, if it weren’t for the bright white eyelights staring upwards out if its sockets.


	2. On a gathering storm comes

**Summary for the Chapter:**

> It feels like a friend.

“HELLO!”  
  
Sans clatters against the wall opposite the opening to the chamber as he throws himself backwards in surprise. He looks up and down the hallway for the source of the voice. He would be in big trouble if his dad found out he was coming here.  
  
“who’s there?” he asked, ignoring his dropped clipboard and swiftly beating soul.  
  
“IT’S ME,” the voice replies, despite there being no monster to claim the pronoun. Sans looks along the floor and ceiling. It would be just his dad’s kind of joke to install a microphone and scare Sans half to dust as punishment.  
  
“very funny, dad,” he decides that’s the most likely solution, even though he hasn’t spotted anything in the walls.  
  
“I’M NOT YOUR DAD… I DON’T THINK.”  
  
“what do you mean, you don’t think?” Sans asks, annoyed. This prank has gone dumb, fast. He was going to have to give his dad some grief for this one. He could have at least written better dialogue.  
  
“WELL, IT’S BEEN A VERY LONG TIME. THEY’VE TAKEN A LOT OF SAMPLES AWAY, AND I DON’T KNOW WHAT THEY DID WITH IT. IMAGINE THAT,” the voice laughs. “I COULD BE A DAD! I’M NOT SURE WHAT DADS DO, BUT I’LL FIGURE IT OUT. NOTHING CAN STUMP ME.”  
  
Sans stares at doorway into the room with it. There’s no way. He couldn’t possibly be entertaining the idea. His curiosity is blazing now, however, so he does. Sans creeps up to the doorway and looks at it.  
  
The eyelights are tilted down in its sockets, directly at him. Sans gasps with fright and backs away. His limbs are shaking and he feels lightheaded. Oh stars, what should he do? He needs to get someone, one of the senior staff. He needs to tell them that it’s speaking to him.  
  
“WAIT, COME BACK! IT’S SO GOOD TO SEE YOU, SON.”  
  
“i’m not your son,” Sans snaps, gathering up his research notes and plotting the best route to the main offices of the labs.  
  
“THEN WHY DID YOU CALL ME ‘DAD’?”  
  
“i didn’t,” Sans isn’t sure why he’s still talking to it. He has everything he needs, but he’s not leaving. He’s too interested in hearing what it says next. “i thought you were someone else.”  
  
“OH, YOUR REAL DAD. THAT DOES MAKE MORE SENSE. ALAS, MY BREIF LIFE AS A DAD COMES TO AN END.” It sighs dramatically. Unexpectedly, Sans laughs. He inches closer to the line.  
  
“so… who are you?” he asks, instead of running off to tell someone about this development. No one will tell him anything about it, so this was his only chance to find out.  
  
“ME? YOU HAVEN’T HEARD OF ME? I’M THE GREAT PAPYRUS!” There’s so much enthusiasm in the declaration that Sans is surprised that it doesn’t get up, even though he knows full well that it’s unable move.  
  
“can’t say that i have,” Sans replies, jotting the name down on the top page of his clip board. “that sounds like a skeleton name,” he comments, looking at the word with a tilt of his skull.  
  
“OF COURSE IT IS. I’M A SKELETON. I WOULD THINK THAT WOULD BE PERFECTLY OBVIOUS.”  
  
Sans looks back up at it, catching its eyelights. It does look perfectly obvious. If it wasn’t for what his dad had said, Sans wouldn’t find Papyrus any different from any other skeleton. So why has Sans been told otherwise?


	3. When you sang your song

**Summary for the Chapter:**

> Curiosity is a powerful drug.

“why didn’t you talk before?” Sans asks, sitting with his back against the short length of wall next to the room with Papyrus in it. His left side is a mere inch away from the line.  
  
“I COULDN’T. IT TOOK ME, WELL, I DON’T HAVE A CLOCK, BUT IT TOOK A LONG TIME TO FIGURE OUT HOW TO TALK WITHOUT MOVING MY MOUTH. BUT, OF COURSE, I MANAGED IT.”  
  
Sans has noticed that Papyrus doesn’t move his mouth to talk. He still can’t move anything except for his eyelights, and they move very slow.  
  
The rest of the staff still doesn’t know. Sans couldn’t bring himself to tell them and lose this opportunity to talk to Papyrus. He keeps promising himself he’ll tell his dad as soon as his curiosity has been sated.  
  
“you’ll have to teach me someday,” he comments, offhanded. Throwing his voice would come in handy for a wide range of pranks.  
  
“OH, I WOULD LOVE TO,” Papyrus responds, “AS SOON AS I’M FREE.”  
  
“f-free?” Sans starts, his hands clutching his knees. A guilty flush covers his cheekbones, and he hopes that Papyrus can’t see it.  
  
“FREE OF THIS ROOM,” Papyrus continues, as if he thinks Sans really doesn’t know. “IT’S VERY BORING IN HERE.”  
  
Sans has no reply for that. He can only imagine, being stuck in that one position for five years- more even. Papyrus was already here when Sans joined the staff. It could have been ten, twenty, a hundred. Laughing under his breath at his own absurdity, Sans reminds himself that Papyrus can’t be a hundred years old. He sounds younger than Sans.  
  
“do you know why you’re in there?” Sans asks, instead. It’s the question that’s burned the brightest in his mind since they started talking.  
  
“DON’T YOU?”  
  
“no,” Sans admits, “they won’t tell me.”  
  
Papyrus is silent for a long moment. The water streams over his bones as Sans waits.  
  
“I DON’T KNOW EITHER. I REMEMBER… RIGHT AFTER WAKING UP. THEY ASKED ME TO DO SOMETHING. I ALWAYS LIKE HELPING, SO I DID IT. BUT THEN THEY STARTED YELLING AND MADE ME COME IN HERE. BEFORE I KNEW IT, I HAD FALLEN, AND I CAN’T GET UP.”  
  
He sounds so sad as he tells the story, so confused. Sans’s soul aches for Papyrus. That didn’t sound anything like the staff, however. They were always so nice, and friendly. There was no way that they had trapped Papyrus here just for doing as they asked.


	4. You're finally free

**Summary for the Chapter:**

> Decisions have been made.

“i don’t know where the control panel is,” Sans says miserably, sitting down by the room.   
  
“THAT’S OKAY. THANK YOU FOR TRYING,” Papyrus sounds as bright and cheerful as always, even though Sans’s attempt to find a way to get him out of the room has failed.   
  
They have been talking for a few weeks now, trading stories and jokes. They can even swap gossip, since the staff never thinks to watch what they say or do around Papyrus. Sans has found out some truly mortifying things about the senior staff. Not his dad, however. Papyrus only ever says that he’s quiet. That did sound like Dr. Gaster when he was around strangers. He only ever loosened up around Sans, and, even then, not around the other staff.   
  
“THERE MAY BE ANOTHER WAY,” Papyrus says hesitantly. Sans perks up, looking over at him.   
  
“what is it?” he asks eagerly. Papyrus has steadily become a friend, and Sans has become less accepting of Papyrus’s situation in proportion.   
  
“I REMEMBER ONE OF THE MONSTERS, I DON’T KNOW WHAT THEY DID, BUT Y- ANOTHER MONSTER SCOLDED THEM FOR ALMOST ‘BREAKING THE FIELD’.”   
  
Sans sits up fully, turning to face Papyrus. Of course! He’s being so stupid. He considers the line on the floor. He can imagine his dad modeling a containment field after the barrier. He might have even made it originally to help him understand the full sized version that kept them trapped underground. That means it was a sphere, and one puncture…  
  
“right, right, so if i just,” he lifts his hand and points a finger at the room, “disrupt the field, it could cause it to collapse.”   
  
“REALLY? BUT ISN’T THE FIELD DANGEROUS FOR YOU?”   
  
Sans smiles. It’s incredibly thoughtful of Papyrus to worry about it hurting him, but what is a little pain if it means his freedom. Besides, Papyrus had been in there for years.   
  
“it will be fine,” he says, and sticks his finger past the line.   
  
It’s agony, pure and simple. There are no other feelings, no emotions. Just pure, undiluted pain. It only lasts a second, but Sans is still gasping when it finally stops, falling forward onto his hands and knees. He can hear something crackling, the electric buzz of machinery gone wrong.   
  
When he looks up, Papyrus is sitting up. His eyelights are fading away, but his skull tilts down to looking at his hands while he moves them experimentally. The water that had been pouring over his rib is hitting the top of his skull now. Bright orange magic ties his joints together, fading as the magic settles in below the bone. The machines along the walls are sparking, probably damaged by the feedback.   
  
“THAT IS MUCH BETTER.” Papyrus stretches, though his freshly made joints have no reason to pop yet. He stands, wavering a bit on his feet, and walks over to Sans. He’s even taller than Sans had imagined.   
  
With a bright smile he helps Sans to his feet. Moving causes a sharp pain in his hand. He looks down to find it sheered off, right above its second joint. Panicked, Sans looks around the floor, but there’s no sign of the missing bone.   
  
“I’M SORRY,” Papyrus is also looking down at the finger. “IT WAS TOO STRONG FOR YOU.”   
  
Sans looks up at him with shock. If the field was strong enough to instantly dust any part of Sans that went inside of it, what has it been doing to Papyrus over the years?   
  
And what is Papyrus that he had survived it? 


	5. I walk with the the Devil

**Summary for the Chapter:**

> There’s no time for regrets.

“this way.”   
  
Sans leads Papyrus through a series of seldom used hallways that lead to various records rooms and labs so old they barely function. If anyone sees a strange skeleton in a hospital gown, they’d know.   
  
Papyrus silently follows him, though every time they pause- so Sans can make sure the coast is clear- he looks around with a muted air. It might be that whatever had happened to him had happened here, but Sans isn’t going to ask.   
  
“Sans?” his father’s brusk voice turns Sans to stone. He’d just stepped out from behind a filing cabinet to scout ahead. Papyrus is still visible in his peripheral vision.   
  
“h-hey,” Sans waves and leans against the cabinet. “what are you doing over here?”   
  
“Research,” Gaster replies dryly. Sans chuckles, hearing the reprimand in the joke. His dad is generally easy-going, but he set the expectation on day one that work comes first.   
  
“oh good, me too,” Sans replies, hoping he sounds casual. That gets him a Look, one brow bone raised, lights peering over the rim of his dad’s glasses. Sans feels like he’s four again when he gets that look.   
  
“You’re hiding something,” Gaster says simply, and it’s clearly not a question.   
  
“n-no,” Sans brushes off the observation, magic starting to trickle down the back of his spine.   
  
“You are behaving strangely, standing so that your body shields that corner from me, and can’t form a single word properly. And what happened to you hand?” Sans has his finger wrapped in gauze he pillaged from a supply closet. “My reasoning skills are known to you Sans. You’ve been found out. Whatever little prank you’ve planned better not have eaten into your lab time today, or I’ll-”   
  
Sans freezes while his dad walks around him to look at Papyrus’s hiding spot. All he can do is follow his father’s progress by turning his skull. He gets as far as lifting his hand from the cabinet when he sees his dad stumble backwards, away from Papyrus. He’s turned his torso when his dad yells for him to run, fear sharp in his voice.   
  
Sans finally completes the turn, no more useful for doing so, as a great big disk appears on the floor behind his dad. It’s pitch black, but there’s some hint of movement inside. It’s a slithery, creepy undulation of forms, none of which can be truly seen in the inky darkness.   
  
And his dad falls backwards into it.   
  
It may be his imagination, but Sans thinks he sees something try to come out as he drops, screaming, from the world, but in the next second it’s gone. The whole disk vanishes without a hint of its existence left.   
  
“what- what the- d-dad… dad!” Sans screams, dropping to his knees. He crawls forward, feeling along the ground for some sign of his father, but it’s just cold, hard linoleum.  
  
“COME ON,” Papyrus grabs his arm and pulls him up to standing. Sans tugs at his hold, trying to get back down to the ground because there has to be something.  
  
“let go of me!” Sans yells, when he finds out that Papyrus is very, very strong. “get away from me. you- you killed him! you killed my dad.”   
  
“HE’S NOT DEAD,” Papyrus replies calmly, none of his intense friendliness gone from his voice. “THAT’S THE MOST MERCY I COULD GRANT HIM, BECAUSE HE’S YOUR DAD.”   
  
Sans goes limp. His dad isn’t dead? He’s still in that place. The thought of it makes him shudder in revulsion. Papyrus walks forward, dragging Sans. He isn’t the least bit worried about anyone seeing them. If he can make them disappear like that, why should he?   
  
“BESIDES, I CAN’T LET YOU GO. I’M GOING TO NEED A FRIEND WHEN I GET OUT THERE.”   
  
“i’m not your friend,” Sans says bitterly, tears starting to make tracks down his face.   
  
“OH,” Papyrus says it with weight, like the denial means something to him. It’s the first thing that’s chipped at his cheerful demeanor. “WE’LL THINK OF SOMETHING ELSE, THEN. I’M NOT YOUR DAD…” Sans winces. “AH! I HAVE IT. WE WERE BOTH MADE BY THE SAME MONSTER. WE CAN BE BROTHERS! IT’S PERFECT…” 

**Notes for the Chapter:**

> That's it! 
> 
> Just a random bit of inspiration from a fan theory I remember reading, like, 2 years ago about Papyrus being not just the stronger brother, but absurdly strong, and Sans is so solicitous of him to keep him from unleashing that power. I didn’t have any interest at the time, but it came back to me all of the sudden as a little bit of horror. 
> 
> Thanks for reading and I hope you enjoyed! <3

**Author's Note:**

> My, oft neglected, SFW tumblr is [here](http://idontevenknowwhatimdoingugh.tumblr.com/), if you have words for me or are interested in the occasional Undertale content.


End file.
